Alpine951

I juust got a motor back in my car and it was running OK for a few weeks until I did a compression check and tried to adjust the idle speed. Now it backfires or burps through the maf cone filter when I blip the throttle through the low rpm range or try to drive it. I might have a vacum leak and was thinking of using a cigar to blow some smoke. Not interested in spending $1K on a smoke machine. I figured I could disconnect the hose at the AOS , which goes directly to the intake manifold on my car which also is venturi delete, no ISV , and has mySwiss vacum ports on the manifold, and blow the cigar smoke into the hose. Will this work?

Ronin-951

Cigar wouldn't do much good for finding a Vac leak on a running car, although a proper 'Smoke Test' [alot more smoke] pressurized into the Intake of a non-running Engine does an 'ok' job of showing bad leaks. Better to use a can of Carb Cleaner or Starting Fluid on all joints and hoses and listen for RPM changes.
Backfire is a Timing issue, so look at the Distributor Rotor and Cap for trouble, or crossfiring Wires. DME control of the Timing leaves little to chance except at Belt changing time.

Landjet

Can a cigar be used to find a vacum leak?
I know it can find an intern

eman930

jc in rb

That intern was a vacuum leak.....

alxdgr8

Go to your local party store and buy a $20 fog machine

ehall

Well Done Sir!

ehall

No. The intern was a Vacuum.

jc in rb

Not according to the black light,she appeared to have a major vacuum leak....

Scott H

No, that was a backfire.

Alpine, I'd recommend you pressurize the intake track using Van's method (search on youtube for 944 turbo intake pressurize) and listen for leaks.

Edit: Just remembered you fixed your problem with the plug wires. Just for future reference, this is a better idea than a cigar/smoke machine.

jimbo1111

The cigar is good for celebrating after you find the leak though.